The 70-year-old woman was handed the sentence at the Kyoto District Court, where Judge Ayako Nakagawa held Chisako accountable for the deaths of three men, including her husband, as well as the attempted murder of another.

"The accused made the victims drink a cyanide compound with a murderous intention in all the four cases," Nakagawa said, according to The Guardian.

Defence lawyers argued that Kakehi was suffering from dementia and was not criminally liable for the deaths but Nakagawa rejected this, describing the cases as "cunning and malicious" and "well prepared in advance."

The British broadcaster noted that Kakehi was indicted for the murder of her fourth husband a month after they got married, in Dec. 2013, and was also accused of killing two other elderly boyfriends as well as the robbery and attempted murder of another boyfriend.